Ebolavirus attacks are devastating and unpredictable. To control an ebolavirus outbreak it is essential to identify, isolate and treat infected individuas rapidly. However, the available diagnostics, ELISA and RT- PCR, require laboratory sophistication that is not possible at point-of-care in many African and other isolated locations. Thus, a portable device that needs no laboratory support is essential to detect early markers of ebolavirus infection. We propose to develop a point-of-care detection device targeting the conserved and highly abundant soluble ebolavirus glycoprotein (sGP), a marker of viral infection that appears in the blood stream early during infection. The detection will be enabled by aptamers attached to microcantilevers. Aptamers are nucleic acids with many of the properties of antibodies, but with the advantage that they are selected and synthesized in vitro and can be reliably reproduced. They can be adapted to many assay formats, including electrochemical, optical (colorimetric, chemiluminescent & fluorescent) and mechanical. Aptamers are very stable when dehydrated and ideal for sensors that must be stored for long time periods before their use for occasional viral outbreaks. As recognition elements for biosensors, aptamers have many advantages over antibodies, including small size, capability for repetitive use, long shelf-life at room temperature while dehydrated, amenability to chemical synthesis and chemical modifications, and adaptability to broad assay formats. Thus, aptamer-based biosensors (aptasensors) are more suitable than antibodies for point-of-care biosensor development. The goal of this proposal is to develop an aptasensor for early diagnosis of ebolavirus infection at point- of-care (either at bedside or at mobile clinic) that will lead to effective treatment and containment of the virus outbreak. We have three specific aims: 1) Use a combination of SELEX, next generation sequencing and bioinformatics to identify DNA aptamers that recognize sGPs from all African ebolavirus species with nanomolar affinity. 2) Build a prototype array of aptamer-functionalized microcantilever device for sGP detection to provide proof of concept for future field application. 3) Assess the efficacy and sensitivity of the detection device for recombinant sGP and sGP in serum from infected macaques. The innovation of this proposal lies in the integration of aptamer and microcantilever detection technologies, which will allow the development of a point-of-care biosensor for early detection of ebolavirus infection based on the appearance of viral sGP in the blood stream. The longer term goal is to expand the capability of the microcantilever aptasensor, which can be multiplexed, to include the detection of other hemorrhagic viruses that present similar symptoms to ebolavirus in the early stages.